10 (1+3x) = -20 and - 5x-8 (1+7x) = -8

With steps

(1)

10 (1+3x) = -20

Cross multiply.

10+30x=-20

Isolate x on one side. So you would subtract 10 on each side. and one side will cross each other out. leaving you with,

30x=-20-10

Subtract 10 from - 20.

30x=-30

Divide each side by 30 to get x.

30x:30=-30:30

Therefore,

x=-1

(2)

-5x-8 (1+7x) = -8

Cross multiply - 8 (1+7x)

-5x-8-56x=-8

Isolate all x's on one side. So you would add 8 on each side. and one side will cross each other out. leaving you with,

-5x-56x=-8+8

Add 8 to - 8.

-5x-56x=0

Subtract - 56x from - 5x

-61x=0

Divide each side by - 61

-61x:-61=0:-61

Therefore,

x=0